The ignition control system for an internal combustion engine is adapted to control the ignition timing at which a high-tension voltage i.e. an ignition pulse is impressed on an ignition plug mounted on a power cylinder of the combustion engine in accordance with fluctuations of the engine speed thereby to perform preferred combution of fuel within the power cylinder.
Various ignition timing control systems have been heretofore developed. In one of such ignition control systems, the ignition timing is kept at a retarded constant level within a lower engine speed range and at an advanced constant level within a middle engine speed range. Within a transitional range between the lower and middle engine speed ranges, the ignition timing is changed generally proportionate to the fluctuations of the instantaneous engine speed.
In another ignition control system, the ignition is forced to cease within a higher speed range.
However, such ignition timing control systems as mentioned above cannot provide a pertinent or satisfactory ignition timing in some cases. In particular, the engine output power is insufficient within a higher engine speed range.
Accordingly, a primary object of the present invention is to provide a new and improved ignition timing control system which can provide a desired ignition timing for an internal combustion engine from a lower engine speed range through a middle engine speed range to a higher engine speed range.
Another object of the present invention is to provide a new an improved ignition timing control system which is reliable in operation.
A still another object of the present invention is to provide a new and improved ignition control system which can precisely control the ignition timing.